1. Field of the Invention
The present invention relates to a copying machine and, more particularly, to a mechanism for cleaning both a charging wire disposed in a charger to charge the surface of a photosensitive drum and a convergent optical system which forms a focused image of an original on the drum surface.
2. Description of the Prior Art
In the known electrophotographic copying machine using a photosensitive drum and toner, there is provided a developing unit for depositing the toner from a developer tank onto the drum surface and a cleaning unit for removing the remaining toner from the drum surface after transfer of the developed toner image to a copy paper. In this structure, however, the toner is prone to scatter from such units during the copying process and thereby becomes suspended throughout the space in the copying machine. Consequently, during long-term use of the copying machine, such suspended toner is deposited on the charging wire of the charger furnished to charge the drum surface and also on the surface of the convergent optical system employed to form a focused image of an original on the drum surface, hence deteriorating the charging efficiency of the charger and reducing the amount of light of an optical image obtained by the convergent optical system. For the purpose of preventing deterioration of the copy image, it has been customary heretofore to periodically clean the charging wire of the charger and the surface of the convergent optical system.
However, in the conventional copying machine, generally the charger needs to be removed therefrom for cleaning, while the convergent optical system is cleaned at the time of maintenance service executed for other components in the machine. Consequently some labor and time are required for cleaning both components which eventually impedes quick periodic maintenance service.